I've been looking to illustrate how/where a worn shifter can be tightened up. I can only see two areas.
The Handle/Input Pivot
The handle mount moves left/right slightly (following the hand motion of the chromed lever) and is pinned a cradle/hinge. If worn, this part will have a forward/backward jiggle of a few thousandths of a an inch, lending to a loose/sloppy feel. My handle feels good and tight (no wiggle), but while inspecting and cleaning it, I noticed a hardened cup washer stuck to the inside of the upper mounting cradle. see attached photo 1
If your handle is loose here, it may be possible to try a different thickness of washer to take up the slack. I have no idea where you would source such (McMaster Carr?).
Shift Lever Throws
As the shifter is opperated, the metal of the throws rotating against each other will wear against each other. There is one plate, between reverse and 1st/2nd, that can not move at all. see attached photo 2
I haven't been able to find a "service limit" definable with feeler gauges anywhere. I have found a plate similar to the one shown in photo 4 on Chicago Corvettes and eBay. It is labeled a "reverse lockout" and is available in two thickness of 5/64" and 7/64". I cannot speak to if those pieces are universal for fit in all Muncie Shifters, but the difference between 5/64" and 7/64" is about .030" which seems about right for tightening up worn shifter throws.
Tips for reassembly
For the Handle Input attached photos 3 & 4
, notice how the handle input's axis pin hole is not centered in the upper cradle. This will help you orient the handle input lever, which should be centered inside the cradle. The hinge pin inserts from the back and the safety clip is visible facing forward.
The parts will generally tell you how they go back together if you look at them. As mentioned previously, the offset of the handle input's hinge hole is a clue, as is how the shift throw plates orient to each other and the lower body. Look for the rectangular "neutral" cutout and the circular notch photo 2, again
The shifter throw order as shown previously
From left to right:
• reverse throw — longest arm length, slight offset bend toward the transmission tail
• reverse lockout plate
• 1st/2nd throw — short arm length with a slight offset bend outward
• 3rd/4th — short arm length with a larger offset bend outward
I'm using moly-grease for fresh lubrication, coating all faces that have metal-to-metal movement. Assembly gets very messy very quickly, so sadly photos were not taken. Assemble the handle input with the upper cradle. Stack the throw arms in their proper order and slide them into the lower casing. Be sure that all notches and cutouts will align correctly. Insert the handle input tongue of the upper cradle assembly into the lower casing with throw arms inserted. The goal here it align the large circular cutouts of all pieces so that the main hinge-pin can slide in. The large hinge-pin inserts from the left/outboard/driver’s side and is secured on the inboard side facing the mounting bracket.